Stevia is a genus of about 240 species of herbs shrubs in the sunflower family (Asteraceae), native to subtropical and tropical regions from Western North America to South America. The species Stevia rebaudiana, commonly known as sweetleaf of Sugarleaf, or simply stevia, is widely grown for its sweet leaves. As a sweetener and sugar substitute, stevia's taste has a slower onset and longer duration than that of sugar.

With its extracts having up to 300 times the sweetness of sugar, stevia has garnered attention with the rise in demand for low-carbohydrate, low sugar food alternatives.

In a few countries, it has been available as a sweetener for decades or centuries; for example; stevia is widely used as a sweetener in Japan where it has been available for decades.

More recent medical research has shown promise in treating obesity and hypertension. Stevia has a negligible effect on blood glucose, even enhancing glucose tolerance; therefore, it is attractive as a natural sweetener to diabetics and other on carbohydrate-controlled diets.